Existing cast shoes or boots are primarily designed for use with a standard, much bulkier plaster cast. Therefore, such shoes or boots are very wide, and do not contour to accommodate the bulk of the plaster casting products. These cast shoes or boots, when used with a newer, thinner, light weight fiberglass cast are much too large, preventing a good fit between the encompassing shoe upper and the fiberglass cast. Because the shoe or boot fits loosely over the cast, it is difficult for the patient to walk well and is potentially hazardous. The variety of shoes or boots in the health care field which have been built or designed to accommodate only one or more needs in that field such as; postoperative support of the feet after surgery, support of a foot carrying the bulkier plaster cast, or such foot accommodating the thinner, light weight fiberglass cast. Attempts have been made to accommodate the cast whether plaster or fiberglass, to facilitate walking and the normal gait of the wearer by providing a rocker bottom to the sole.
Patents representative of the development within these related arts, include U.S. Pat. No. 3,661,151 to Schoenbrun et al. directed to a converted shoe as an aid in the post-operative rehabilitation of a foot while serving as a splint or cast for foot fracture. The shoe is characterized by a rigid plywood mid-sole to restrict undesirable foot movement during ambulation has an open toe and eliminates the conventional tongue while employing laces to adjust or compensate for swelling of the foot. The bottom sole is ribbed with the shoe having a heel portion of the sole assembly which is thicker than that at the toe.
U.S. Pat. No. 3,848,287 to Simonson which teaches a shoe molded to the foot, has no application to the foot bearing a cast, either of the bulky plaster or the slim fiberglass type, is not formed over a last, and is devoid of a rocker bottom.
U.S. Pat. No. 4,454,871 to Mann et al. teaches a molded product replacing a plaster cast metal bracing or the like for immobilizing the ankle joint to promote healing and which facilitates immediate ambulation after application which includes a shallow V-shaped rubber sole bottom surface which may be rippled, which provides a rocker effect and in which the molded sides can be drawn together by binding straps for partially closing the opening to snugly fit the orthosis to the wearer.
U.S. Pat. No. 4,414,759 to Morgan et al. teaches an orthopedic shoe and post-operative structure having a convex bottom sole ribbed surface to simulate the natural motion of the foot in walking. A shoe upper has wrap-around straps for binding flexible side flaps in overlapping position about the top of the foot of the user and uses straps fixing to each other a VELCRO.RTM. material at the unsecured ends of a pair of such straps secure the orthopedic shoe to the foot. The post-op shoe is limited to use after surgery to the foot and is no application to a casted foot.
In the area of casted foot protection U.S. Pat. No. 4,454,872 to Brouhard teaches a wrap-around protective device for human toes when the foot is encased in an orthopedic cast but is not a medical shoe or boot.
U.S. Pat. No. 4,677,767 to the Applicant is directed to a post-operative shoe, is devoid of a rocker sole, is not intended and normally incapable of being worn with a cast, either of plaster or the light weight fiberglass type. However, the shoe does evidence the use of overlapping flaps and VELCRO.RTM. tipped straps for applying the post-operative shoe to the patient after surgery.
It is therefore a primary object of the present invention to provide an improved cast shoe or boot, which form fits to a cast borne by the foot of the wearer, which is constructed over a last, which is applicable to treatment of other deformities and lesions, and which contours more closely to the contour of the human foot.
It is a further object of the invention to provide a cast boot or shoe of this type, whose outer sole may be constructed of foam, is provided with a double rocker bottom, preferably a ribbed outer surface which makes use of two longitudinally spaced pivot points one of which is at the ball of the foot to ensure that the casted foot moves through the gait cycle smoothly and with the first pivot point located approximately 30% down the length of the shoe, measuring from the heel to the toe and which takes the form of roughly flat central bottom surface with upwardly oblique flat front and rear bottom surfaces.